What's a little like Wordle, just as free and you can make the words fit an image- Tagxedo.comHere are a few I created for our Education 2020 wiki. I took a bunch of the words from our initial proposal, found an image of a light bulb and then tweek a bit here and there..voila!

In the next one for Curriculum, I did the basic tag picture in Tagxedo, then brought it into Photoshop and added a few words to emphasize a few key concepts.